“He proposed to Sienna during their romantic trip to Paris after Christmas. He filled their hotel suite at the Ritz with flowers and presented her with a vintage Victorian ring. It was incredibly romantic (and) she was blown away.”

Miller had a seven-year on/off romance with actor Jude Law, which ended for good last year. Sturridge has been linked to actresses Camilla Belle and Carey Mulligan.

The couple is expecting its first child in June.

Publicists for both Miller and Sturridge have yet to confirm the baby news and the reports the pair is set to wed.